Hydrocarbon reserves are becoming increasingly difficult to locate and access, as the demand for energy grows globally. As a result, various technologies are utilized to collect measurement data and then to model the location of potential hydrocarbon accumulations. The modeling may include factors, such as (1) the generation and expulsion of liquid and/or gaseous hydrocarbons from a source rock, (2) migration of hydrocarbons to an accumulation in a reservoir rock or to the surface, (3) a trap and a seal to prevent significant leakage of hydrocarbons from the reservoir. The collection of data, such as marine surveying approaches, may be beneficial in modeling potential location for subsurface hydrocarbon accumulations.
One conventional marine surveying approach involves remote sensing an area of interest. For example, reflection seismic is the dominant remote sensing technology for the identification of hydrocarbon accumulations. This approach has been successful in identifying structures that may host hydrocarbon accumulations, and may also be utilized to image the hydrocarbon fluids within subsurface accumulations as direct hydrocarbon indicators (DHIs). However, this approach may lack the required fidelity to provide accurate assessments of the presence and volume of subsurface hydrocarbon accumulations due to poor imaging of the subsurface, particularly with increasing depth where acoustic impedance contrasts that cause DHIs are greatly diminished or absent. Further, non-seismic hydrocarbon detection technologies, such as potential field methods like gravity or magnetics or the like, provide coarse geologic subsurface controls by sensing different physical properties of rocks, but lack the fidelity to identify hydrocarbon accumulations. As such, the conventional approaches may merely provide guidance on where a basin seismic survey should be conducted, but do not significantly improve the ability to confirm the presence of hydrocarbon seeps or subsurface hydrocarbon accumulations.
Other conventional marine surveying may involve the use of manned vessels or vehicles to collect samples. See, e.g., American Standards and Testing Association's Standard Practice D4489. However, such sampling approaches are expensive due to the vessel deployment requirements and the number of samples is limited by the amount of time a vessel and its crew can remain on the body of water to perform operations. Further, samples obtained from the manned vessel's operations may fail to obtain samples from a target of interest or include samples that are compromised due to marine vessel traffic or other disturbances. As a result, the conventional approaches may provide a limited coverage area, may require certain amounts of lead time to prepare and deploy the vessel and crew, may involve additional verification steps to confirm a target of interest is present because of the delays in deployment, and may provide limited flexibility for adjusting a course plan or trajectory during operations (e.g., real-time or concurrent adjustments). As such, manned marine surveying approaches have various limitations for surveying operations.
Yet another approach for marine surveying may include remote sensing coupled with a sampling operations. This approach may be used to identify possible features of interest (e.g., oil slicks from seeps, red tide or a chemical pollutant) or wildlife (e.g., invasive, rare, threatened or endangered species locations). The remote sensing may be performed indirectly (e.g., with satellite or airborne imaging) or directly (e.g., via observations and sampling from a marine vessel). Then, a marine vessel can be deployed with a manned crew to determine the location of the observation and to obtain samples. However, similar to the discussion above regarding manned approaches, the deployment of a marine vessel may be time consuming and expensive to operate. Further, because the deployment involves processing remote sensing data and the deployment may involve delays, this approach may not be able to locate the ephemeral feature, as it is not performed in a timely manner. That is, the target or feature may have aged, dissipated, or moved to a different location as a result of changes in conditions, such as currents and/or wind. In addition, a chemical associated with the target may have to involve high concentrations to be detected and may have to be at the surface to be discernable via satellite or aircraft. Also, this approach may have difficulties in addressing and overcoming limitations from noise (e.g., signal to noise ratio in processing of the data). These difficulties may be a result of the problems of determining background levels present within a certain body of water and identifying anomalies as compared to the background levels, and then to locate anthropogenic sources that may not persist over time. Thus, this approach has additional limitations.
As a result, enhancements to marine surveying approaches are needed. In particular, marine surveying may include obtaining samples of biological origin, hydrocarbons and/or chemicals, which may be used to enhance hydrocarbon exploration, hydrocarbon development, and/or environmental monitoring of bodies of water with one or more buoys. The obtained samples may also provide biodiversity data at different trophic levels, through the analysis of environmental deoxyribonucleic acid (eDNA), which may provide useful information on the impact of an event or ongoing anthropomorphic features, for waterborne pathogens and for studying invasive or endangered species. These techniques may efficiently obtain samples from waterborne liquid hydrocarbons for indicators of a working hydrocarbon system in exploration areas, which may then be used to enhance basin assessment and to high-grade areas for further exploration.